Aeromonas aminopeptidase (AAP) is a bimetallic zinc hydrolase that cleaves a peptide bond to release the N-terriiinal amino residue. Although the structure was solved to 1.8 angs resolution, it is unknown whether the bridging molecule is a water or a hydroxide ion. In other words, at what point in AAP's catalytic mechanism is water activated? What is the bridging metal species? And what are the positions of the catalytically important protons and atoms? A high-resolution data set of AAP may provide answers to some of these questions. In-house, AAP crystals have diffracted well to the limits of our detectors, 1.6 angs. I believe that with a shorter wavelength and a 2theta arm, resolution of better than 1.2 angs can be achieved. Data was collected on BioCARS Station 14-BM-C.